-It is possible to set default values that will be used in every method in your Action Mailer class. To implement this functionality, you just call the public class method <tt>default</tt> which you get for free from <tt>ActionMailer::Base</tt>. This method accepts a Hash as the parameter. You can use any of the headers e-mail messages has, like <tt>:from</tt> as the key. You can also pass in a string as the key, like "Content-Type", but Action Mailer does this out of the box for you, so you won't need to worry about that. Finally, it is also possible to pass in a Proc that will get evaluated when it is needed.

+It is possible to set default values that will be used in every method in your Action Mailer class. To implement this functionality, you just call the public class method <tt>default</tt> which you get for free from <tt>ActionMailer::Base</tt>. This method accepts a Hash as the parameter. You can use any of the headers email messages have, like <tt>:from</tt> as the key. You can also pass in a string as the key, like "Content-Type", but Action Mailer does this out of the box for you, so you won't need to worry about that. Finally, it is also possible to pass in a Proc that will get evaluated when it is needed.

Note that every value you set with this method will get overwritten if you use the same key in your mailer method.

The test suite runs with warnings enabled. Ideally, Ruby on Rails should issue no warnings, but there may be a few, as well as some from third-party libraries. Please ignore (or fix!) them, if any, and submit patches that do not issue new warnings.

-As of this writing (December, 2010) they are especially noisy with Ruby 1.9. If you are sure about what you are doing and would like to have a more clear output, there's a way to override the flag:

+If you are sure about what you are doing and would like to have a more clear output, there's a way to override the flag: